This Application is a 371 of PCT/DE98/03457.
The present invention relates to a method and a device for stabilizing a vehicle to prevent overturning.
German Patent No. 32 22 149 concerns a device for preventing the lateral overturning of a vehicle. This vehicle is a van-carrier (gantry-lift). The device contains a device for calculating the static stability of the vehicle, as a critical reference value, from the quotient of the vehicle tread width and the double height of the overall center of gravity. Moreover, the device contains a device for calculating the dynamic instability from the quotient of the squared vehicular speed and the product of the cornering radius calculated from the specific steering angle and the gravitational acceleration. When the dynamic instability exceeds the reference value, then the vehicular speed is reduced. This is carried out, first of all, by activating the vehicle brakes and, secondly, by activating the engine clutch correspondingly.
German Published Patent Application No. 44 16 991 concerns a method and a device for alerting the driver of a truck about overturn danger during cornering. To this end, prior to the vehicle entering a curve, the vehicle type and the condition data which is relevant for the overturn danger are ascertained, and the overturn risk, or the limit speed decisive for the latter, is determined as a function of the vehicle""s center of gravity and of the cornering radius. A signal prompting for speed reduction is triggered when the prevailing driving speed of the vehicle constitutes an overturn danger or when a predefined safety distance from the overturn danger is undershot. The driving speed of the vehicle at which definitely no overturn risk exists is determined on the basis of an overturn equation. Entering into the overturn equation are, inter alia, the vehicular speed, the cornering radius driven through by the vehicle, the height of the center of gravity of the vehicle above the roadway, as well as the unbalance of the wheel loads. The wheel loads are ascertained by wheel load sensors embedded in the roadway. If the driving speed of the vehicle falls below a predefined safety distance from the driving speed which is at the verge of the overturn danger, then a signal is generated which alerts the drive of the vehicle about excessive speed while driving through the curve. The signal indicating the excessive driving speed is triggered until the specific measured driving speed is reduced to a degree which rules out any risk of overturning.
An object of an exemplary method of the present invention and of an exemplary embodiment of the present invention involves providing that a quantity describing or corresponding to the wheel behavior of at least one wheel is considered in the determination of a quantity which describes whether an overturn tendency exists for the vehicle, in particular an overturn tendency about a vehicle axis oriented in the longitudinal direction of the vehicle. For this reason, it is possible to respond faster to an overturn tendency since the overturn of a vehicle becomes noticeable first in the wheel behavior.
An object of an exemplary method of the present invention and of an exemplary embodiment of the present invention involves providing that the instantaneous friction conditions are considered in the determination of the characteristic value for the quantity describing the lateral dynamics of the vehicle. Because of this, the road conditions, which influence the overturn behavior of a vehicle, are taken into account and, consequently, it is believed that accuracy is improved.
An object of an exemplary method of the present invention and of an exemplary embodiment of the present invention involves providing that they are suitable for combinations, articulated road trains, busses, as well as for passenger cars having a high center of gravity such as vans or off-road vehicles, i.e., that they can be used for different